1. Technical Field
The present invention relates to portable computers, and more particularly to a portable computer having a touch pad input device in which inadvertent operation of the touch pad can be prevented during keyboard input operation.
2. Related Art
Computer systems are information handling systems that are utilized by many individuals and businesses today. A conventional computer system can be defined as a microcomputer that includes a central processing unit (CPU), a volatile memory, a non-volatile memory, a display monitor, a keyboard, an input device for cursor control such as a mouse, a floppy diskette drive, a compact disc-read only memory (CD-ROM) drive, a modem, a hard disk storage device, and a printer. Typically, a computer system's main board, which is a printed circuit board known as a motherboard, is used to electrically connect these components together.
Portable computers are often referred to as laptop, notebook, or sub notebook computers. These computers typically incorporate a flat panel display such as a liquid crystal display (LCD) or other relatively small display. Typically, portable computers are equipped with pointing devices for enabling input of coordinate data, selection of a menu, moving of an object, and so forth. Examples of pointing devices include a mouse, a track ball, a stylus, a touch pad, and others. The typical pointing device of the portable computer may include a track ball, track point, and touch pad. These portable computer pointing devices are incorporated into the main body of the portable computer for their compact fit for the smaller size of the portable computer. Also, buttons are provided onto the surface of the main body to be pressed or clicked manually and to control certain functions that may be customized to suit the user.
Modem notebook computers often adopt the touch pad for its flat and compact structure. The touch pad is usually mounted in the midst of palm rest portion of the notebook computer, and in particular placed below "space" bar of the keyboard. Moving the mouse pointer is possible by moving a finger on the touch pad, and clicking operation can be made by touching a finger onto the touch pad.
However, during the keyboard input operation, problems arise in such a touch pad pointing device that the pointing operation can be made inadvertently by the movement of fingers. Particularly, thumbs are apt to be touched at the touch pad unconsciously since the touch pad is located adjacent the thumb position of the keyboard. In this case, an insertion point can be moved to wrong position on screen and one may make an error in key input in an application program such as a word processor program.
Attempts have been made to avoid inadvertent operation of the touch pad by adjusting the touch pad size or by changing the location of the touch pad. I believe these attempts have been unsuccessful because the inadvertent operation of the touch pad still occurs. In addition, these attempts have created design problems because the location of the touch pad and the size of the touch pad can limit design options of portable computers.
Exemplars of recent efforts in the art include U.S. Pat. No. 5,666,113 for a System for Using a Touchpad Input Device for Cursor Control and Keyboard Emulation issued to Logan, U.S. Pat. No. 4,899,138 for a Touch Panel Control Device with Touch Time and Finger Direction Discrimination issued to Araki et al., U.S. Pat. No. 5,404,458 for a Method and Apparatus Recognizing the Cessation of Motion of a Pointing Device on a Displays by Comparing a Group of Signals to an Anchor Point issued to Zetts, U.S. Pat. No. 5,327,161 for a System and Method for Emulating a Mouse Input Device with a Touchpad Input Device issued to Logan et al., and U.S. Pat. No. 5,764,218 for a Method and Apparatus for Contacting a Touch-sensitive Cursor-controlling Input Device to Generate Button Values issued to Della Bona et al.
Although various types of touch pads for computers currently exist, I have discovered that there is a need to provide an improved touch pad input control function for a portable computer.